Toward novel polyacetals by transacetalation techniques: dendrimeric diacetals.

[structure: see text] A new approach to polyacetal systems using sequential transacetalation and protection-deprotection techniques was developed for the preparation of macromolecular polyacetals and applied to secure new dendrimers with 2,4,8,10-tetraoxaspiro[5,5]undecane dendrons from pentaerythritol and polyaldehydes. These novel dendrimers, featuring a 1,3,5-benzene-tricarbaldehyde core, viz., the dodecaol (18) and its hexaacetal (19), were prepared, and molecular modeling revealed peculiar dendron convergent structures above the core, due to intramolecular pi-stacking interactions, reinforced by H-bonding of multifunctional termini.